diff options
Diffstat (limited to 'bootblocks/bzimage.c')
| -rw-r--r-- | bootblocks/bzimage.c | 555 |
1 files changed, 555 insertions, 0 deletions
diff --git a/bootblocks/bzimage.c b/bootblocks/bzimage.c new file mode 100644 index 0000000..8d38753 --- /dev/null +++ b/bootblocks/bzimage.c @@ -0,0 +1,555 @@ +/* + * Load and execute a bzImage file from the device the 'open_file' and + * friends use. + */ + +#include <stdio.h> +#include "i86_funcs.h" +#include "readfs.h" + +int auto_flag = 1; +char * append_line = 0; /* A preset append line value */ + +static char * initrd_name = 0; /* Name of init_ramdisk to load */ +static int vga_mode = -1; /* SVGA_MODE = normal */ + +static char * read_cmdfile(); +static char * input_cmd(); + +cmd_bzimage(ptr) +char * ptr; +{ + char * image; + int ch; + + if( (auto_flag=(ptr==0)) ) ptr=""; + + while(*ptr == ' ') ptr++; + image = ptr; + while(*ptr != ' ' && *ptr) ptr++; + ch = *ptr; + *ptr = '\0'; + if( ch ) ptr++; + while(*ptr == '\n' || *ptr == ' ') ptr++; + + if( *ptr == '\0' ) ptr = 0; + if( *image ) + bzimage(image, ptr); + else + bzimage("vmlinuz", ptr); +} + +bzimage(fname, command_line) +char * fname; +char * command_line; +{ + char buffer[1024]; + long len; + char * ptr; + int low_sects; + unsigned int address; + + if( open_file(fname) < 0 ) + { + if( auto_flag == 0 ) + printf("Cannot find file %s\n", fname); + return -1; + } + + printf("Loading %s\n", fname); + + if( read_block(buffer) < 0 || check_magics(buffer) < 0 ) + { + printf("File %s isn't a bzImage.\n", fname); + return -1; + } + + if( boot_mem_top < 0x9500 ) + { + printf("There must be 640k of boot memory to load Linux\n"); + return -1; + } + + /* Guestimate how much the uncompressed kernel will use. + * I expect we could lookup the size in the gzip header but + * this is probably close enough (3*the size of the bzimage) + */ + len = file_length() * 3 / 1024; + if( main_mem_top < len ) + { + printf("This kernel needs at least %ld.%ldM of main memory\n", + len/1024, len*10/1024%10); + return -1; + } + if( main_mem_top < 3072 ) + printf("RTFM warning: Linux really needs at least 4MB of memory.\n"); + + low_sects = buffer[497] + 1; /* setup sects + boot sector */ + address = 0x900; + + /* load the blocks */ + rewind_file(); + for(len = file_length(); len>0; len-=1024) + { + int v; + + printf("%ldk to go \r", len/1024); fflush(stdout); + + v = (bios_khit()&0x7F); + if( v == 3 || v == 27 ) + { + printf("User interrupt!\n"); + bios_getc(); + return -1; + } + + if( read_block(buffer) < 0 ) + { + printf("Error loading %s\n", fname); + return -1; + } + + for(v=0; v<1024; v+=512) + { + if( putsect(buffer+v, address) < 0 ) + return -1; + + address += 2; + + if( low_sects ) + { + low_sects--; + if( low_sects == 0 ) address = 0x1000; + } + } + } + + /* Yesss, loaded! */ + printf("Loaded, "); fflush(stdout); + + /* Ok, deal with the command line */ + if( build_linuxarg(auto_flag, fname, append_line, command_line) < 0 ) + return -1; + + if( initrd_name ) + if( load_initrd(address) < 0 ) + return -1; + + printf("Starting ...\n"); + + if( x86 < 3 ) + { + printf("RTFM error: Linux-i386 needs a CPU >= 80386\n"); + if( !keep_going() ) return -1; + } + + if( a20_closed() ) open_a20(); + if( a20_closed() ) + { + printf("Normal routine for opening A20 Gate failed, Trying PS/2 Bios\n"); + bios_open_a20(); + } + if( a20_closed() ) + { + printf("All routines for opening A20 Gate failed, if I can't open it\n"); + printf("then Linux probably can't either!\n"); + if( !keep_going() ) return -1; + } + + /* Patch setup to deactivate safety switch */ + __set_es(0x9000); + __poke_es(0x210, 0xFF); + + /* Set SVGA_MODE if not 'normal' */ + if( vga_mode != -1 ) __doke_es(506, vga_mode); + + /* Default boot drive is auto-detected floppy */ + if( __peek_es(508) == 0 ) __poke_es(508, 0x200); + + /* Finally do the deed */ + { +#asm + ! Kill the floppy motor, needed in case the kernel has no floppy driver. + mov dx,#0x3f2 + xor al, al + outb + + ! Setup required registers and go ... + mov ax,$9000 + mov bx,$4000-12 ! Fix this to use boot_mem_top + mov es,ax + mov ds,ax + mov ss,ax + mov sp,bx + jmpi 0,$9020 ! Note SETUPSEG NOT INITSEG +#endasm + } +} + +check_magics(buffer) +char * buffer; +{ + /* Boot sector magic number */ + if( *(unsigned short*)(buffer+510) != 0xAA55 ) return -1; + + /* Setup start */ + if( memcmp(buffer+0x202, "HdrS", 4) != 0 ) return -1; + + /* Setup version */ + if( *(unsigned short*)(buffer+0x206) < 0x200 ) return -1; + + /* Check load flags for bzImage */ + if( (buffer[0x211] & 1) == 0 ) return -1; + + /* Code 32 start address */ + if( *(unsigned long*)(buffer+0x214) != 0x100000 ) return -1; + + return 0; +} + +putsect(buffer, address) +char * buffer; +unsigned int address; +{ + int rv, tc=3; +retry: + tc--; +#if 1 + if( x86_emu ) + { +static unsigned int last_address = 0; + if( address <= last_address ) + printf("Problem %d<=%d\n", address, last_address); + if( address < 0xA00 ) + { + int i; + __set_es(address*16); + for(i=0; i<512; i++) + __poke_es(i, buffer[i]); + } + return 0; + } +#endif + if( (rv=ext_put(buffer, address, 512)) != 0 ) + { + switch(rv) + { + case 1: + printf("Parity error while copying to extended memory\n"); + break; + case 2: + printf("Interrupt error while copying to extended memory\n"); + if ( tc>0 ) goto retry; + break; + case 3: + printf("BIOS cannot open A20 Gate\n"); + break; + case 0x80: case 0x86: + printf("BIOS has no extended memory support\n"); + break; + default: + printf("Error %d while copying to extended memory\n", rv); + break; + } + if( x86 < 3 ) + printf("RTFM error: Linux-i386 needs a CPU >= 80386\n"); + else if( x86_emu ) + printf("RTFM error: Linux-i386 cannot be run in an emulator.\n"); + return -1; + } + return 0; +} + +static char * +read_cmdfile(iname, extno) +char * iname; +int extno; +{ + char buffer[1024]; + char buf[16]; + long len; + char * ptr = strchr(iname, '.'); + + buf[8] = '\0'; + strncpy(buf, iname, 8); + switch(extno) + { + case 1: strcat(buf, ".cmd"); break; + case 2: strcat(buf, ".app"); break; + case 3: strcat(buf, ".dfl"); break; + default: return 0; + } + + if( ptr == 0 && open_file(buf) >= 0 ) + { + /* Ah, a command line ... */ + if( extno == 1 ) printf("Loading %s\n", buf); + len = file_length(); + if( len > 1023 ) + { + printf("Command line file %s truncated to 1023 characters\n", buf); + len = 1023; + } + if( read_block(buffer) >= 0 ) + { + int i; + for(i=0; i<len; i++) + if( buffer[i] < ' ' ) buffer[i] = ' '; + buffer[len] = '\0'; + + return strdup(buffer); + } + } + return 0; +} + +char * +input_cmd(iname) +char * iname; +{ + char buffer[1024]; + char lbuf[20]; + int cc; + + for(;;) + { + printf("%s: ", iname); fflush(stdout); + + cc = read(0, buffer, sizeof(buffer)-1); + if( cc <= 0 ) return 0; + buffer[cc] = 0; + if( cc == 1 && *buffer != '\n' ) + { + putchar('\n'); + cc = (buffer[0] & 0xFF); + + if( cc == 0xAD ) /* ALT-X */ + return 0; + + sprintf(lbuf, "$%02x", cc); + cmd_help(lbuf); + continue; + } + if( buffer[cc-1] == '\n' ) buffer[cc-1] = '\0'; + + break; + } + + return strdup(buffer); +} + +build_linuxarg(auto_flg, image, append, cmd) +int auto_flg; +char *image, *append, *cmd; +{ +static char * auto_str = "auto"; +static char * image_str = "BOOT_IMAGE="; + int len = 0; + char * ptr, *s, *d; + + char * free_cmd = 0; + char * free_app = 0; + char * free_dfl = 0; + + if( append == 0 ) + append = free_app = read_cmdfile(image, 2); + + if( cmd == 0 ) + cmd = free_cmd = read_cmdfile(image, 1); + + if( cmd == 0 ) + free_dfl = read_cmdfile(image, 3); + + close_file(); /* Free up loads a room */ + + if( cmd == 0 ) + { + cmd = free_cmd = input_cmd(image); + auto_flg = 0; + } + + if( cmd == 0 ) + { + printf("Aborted execution\n"); + return -1; + } + else if( *cmd == 0 ) + cmd = free_dfl; + + if( auto_flg ) len += strlen(auto_str) + 1; + if( image ) len += strlen(image_str) + strlen(image) + 1; + if( append ) len += strlen(append) + 1; + if( cmd ) len += strlen(cmd) + 1; + + if( len == 0 ) return 0; + + ptr = malloc(len+1); + if( ptr == 0 ) + { + printf("Unable to create linux command line\n"); + if( free_cmd ) free(free_cmd); + if( free_app ) free(free_app); + if( free_dfl ) free(free_dfl); + return -1; + } + + *ptr = 0; ptr[1] = 0; + if( auto_flg ) { strcat(ptr, " "); strcat(ptr, auto_str); } + if( image ) { strcat(ptr, " "); strcat(ptr, image_str); strcat(ptr, image); } + if( append ) { strcat(ptr, " "); strcat(ptr, append); } + if( cmd ) { strcat(ptr, " "); strcat(ptr, cmd); } + + if( free_cmd ) free(free_cmd); + if( free_app ) free(free_app); + if( free_dfl ) free(free_dfl); + + if( (d = malloc(len+1)) == 0 ) + { + printf("Unable to compact linux command line\n"); + free(ptr); + return -1; + } + *d = '\0'; + for(s=strtok(ptr, " "); s; s=strtok((char*)0, " ")) + { + if( strncmp(s, "vga=",4) == 0 ) + { + if( strncmp(s+4, "ask", 3) == 0 ) + vga_mode = -3; + else + { + s+=4; getnum(&s, &vga_mode); + } + } + else if( strncmp(s, "ramdisk_file=", 13) == 0 ) + { + if( initrd_name ) free(initrd_name); + if( s[13] ) + initrd_name = strdup(s+13); + else + initrd_name = 0; + } + else + { + strcat(d, " "); + strcat(d, s); + } + } + free(ptr); ptr = d; + len = strlen(ptr); + + if( len > 2048 ) + { + printf("Linux command line truncated to 2047 characters\n"); + ptr[2048] = 0; + len = 2048; + } + + __set_es(0x9000); + __doke_es(0x0020, 0xA33F); + __doke_es(0x0022, 0x4000); + + __movedata(__get_ds(), (unsigned)ptr+1, 0x9000, 0x4000, len); + + free(ptr); + + return 0; +} + +keep_going() +{ +static int burning = 0; + char buf[1]; + int cc; + + printf("Keep going ? "); fflush(stdout); + + cc = read(0, buf, 1); + if( cc == 1 && (*buf == 'Y' || *buf == 'y') ) + { + printf("Yes, Ok%s\n", burning?"":", burn baby burn!"); + return burning=1; + } + printf("No, Ok returning to monitor prompt\n"); + return 0; +} + +load_initrd(k_top) +unsigned int k_top; +{ + unsigned int address, rd_start, rd_len; + long file_len; + char * fname = initrd_name; + + char buffer[1024]; + + /* Top of accessable memory */ + if( main_mem_top >= 15360 ) address = 0xFFFF; + else address = 0x1000 + main_mem_top*4; + + if( *initrd_name == '+' ) + { + char buf[2]; + fname++; + close_file(); + printf("Insert root floppy and press return:"); fflush(stdout); + read(0, buf, 2); + } + + if( open_file(fname) < 0 ) + { + printf("Cannot open %s\n", fname); + return -1; + } + file_len = file_length(); + rd_len = (file_len+1023)/1024; + + if( file_len > 15000000L || k_top + rd_len*4 > address ) + { + printf("Ramdisk file %s is too large to load\n", fname); + return -1; + } + + rd_start = address - rd_len*4; + rd_start &= -16; /* Page boundry */ + address = rd_start; + + printf("Loading %s at 0x%x00\n", fname, rd_start); + + for( ; rd_len>0 ; rd_len--) + { + int v = (bios_khit()&0x7F); + if( v == 3 || v == 27 ) + { + printf("User interrupt!\n"); + bios_getc(); + return -1; + } + + printf("%dk to go \r", rd_len); fflush(stdout); + if( read_block(buffer) < 0 ) + { + printf("Read error loading ramdisk\n"); + return -1; + } + if( putsect(buffer, address) < 0 ) return -1; + address+=2; + if( putsect(buffer+512, address) < 0 ) return -1; + address+=2; + } + printf("Loaded, "); + + /* Tell the kernel where it is */ + { + long tmp = ((long)rd_start << 8); + + __set_es(0x9000); + __doke_es(0x218, (unsigned) tmp); + __doke_es(0x21A, (unsigned)(tmp>>16)); + + __doke_es(0x21C, (unsigned) file_len); + __doke_es(0x21E, (unsigned)(file_len>>16)); + } + + return 0; +} |